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SLEEP STUDY: WHAT'S IT ALL ABOUT
BRIAN KOO, M.D.Ass is tan t Profes sor of Neurology
Yale Sc hool of Medic ineDirec tor, S leep Medic ine Program at
Connec ticu t Veterans Af fair s Healthcare
OUTLINE
Polysomnography What Is It? How Do I prepare for it? Why Would My Doctor Order it?/Why Might I need a sleep study? How is a sleep study interpreted?
What Happens Next?
WHAT YOU MIGHT LOOK LIKE
POLYSOMNOGRAPHIC RECORDING
Electroencephography (EEG): Sleep potentials mostly central
Electrooculography (EOG): Cornea: (+) charge; Retina: (-)charge
Electromyography (EMG): Chin muscle tone
SLEEP STUDY: LOGISTICS
Get there at 8-9PM.
Education about sleep disorder, mostly sleep apnea
Maybe fit for a mask if it is needed later
Sleep studies lasts from about 10-11PM until 5-6AM
Hook-up will take 30 minutes
Some paste on the scalp for EEG
Other electrodes placed with sticky sensors
It is not painful
30 SECOND EPOCH
STAGES OF SLEEPState Eye
MovementsEEG Chin EMG
RestingWakefulness
RapidFrequent
Mixed freqα: 8-12 Hz
High
Stage 1 (N1) Slow rolling θ Low
Stage 2 (N2) Infrequent θ, δ Low
Stage (N3) Infrequent δ Low
REM Sleep Rapid Mixed freq Low amplitude
Atonia
–Stage 1 –Stage 2 –SWS–REM
2-5%45-55%15-20%20-25%
STAGES OF SLEEPn Resting wakefulness
n EEG: α 8-12 Hz ■ Few eye movemenn Best seen eyes closed ■ High chin EMG
FALLING ASLEEP
STAGE 1 NREM SLEEP
STAGE 2 NREM SLEEP
STAGE 3 NREM SLEEP
REM SLEEP
HYPNOGRAM
14
� Technician or fellow stages each epoch of sleep
Breathing
15
NORMAL BREATHING
HOW DO I PREPARE FOR IT
Bring yourself on time
Do not drink alcohol that day or night
Do not drink caffeine after 12PM
Do not take a nap
If you take a sleeping medication, it is OK to take it unless your doctor tells you otherwise
If you wear a mouthpiece for bruxism, wear it unless your doctor tells you otherwise
WHY DID MY DOCTOR ORDER ONE?
By far the most common indication for a sleep study is to determine if there is sleep apnea.
OBSTRUCTIVE SLEEP APNEARepetitive decreases / cessations in breathing associated with loud snoring, witnessed apneas, waking up choking/gasping and excessive daytime sleepiness
OBSTRUCTIVE APNEAObstructive apnea: cessation in breathing ≥ 10 seconds with continued breathing effort often assoc with ≥ 3% O2 desaturation or arousal; 90% reduction in thermistor signal Obstructive Apnea
HYPOPNEAHypopnea: decrement of breathing by ≥ 30% (nasal pressure) for at least 10 seconds MUST BE assoc with ≥ 3% O2 desaturation arousal Hypopnea
CENTRAL SLEEP APNEARepetitive cessations in breathing and effort often but not necessarily associated with ≥ 3% O2 desaturation or arousal
Mild snoring
Witnessed apnea
Waking up gasping for air
Mild daytime sleepiness
SEVERE APNEA
SLEEP APNEA SEVERITY
Apnea-hypopnea index (AHI) = (apneas + hypopneas)
Mild: between 5 and 15 Moderate: between 15 and 30 Severe: Greater than 30
AHI does not distinguish obstructive vs. central
Distinction must be made in physician interpretation
Sleep (hrs)
OBSTRUCTIVE SLEEP APNEA
•AHI ≈ 90 ¡ Severe desaturation (60s)
•Sleep fragmentation
OTHER INDICATIONS
REM sleep behavior disorder Acting out dreams Often injury to self or bed partner
Parasomnia Sleep walking, night terror
Seizure May do full montage EEG
THESE ARE NOT INDICATIONS
Insomnia
RLS: RLS diagnosis is made in the office by history
Sleep study can be done in those with insomnia or RLS if sleep apnea or parasomnia is suspected.
OTHER THINGS THAT CAN BE SEEN IN PSG
Some things that are recorded on PSG Trying to see if these exist are not necessarily indications for a sleep study
PERIODIC LIMB MOVEMENTS DURING SLEEP
INDIVIDUAL LEG MOVEMENTS
Individual limb movementsDorsiflexion of foot (anterior tibialis)Dorsiflexion great toe and extension of toesFlexion at kneeFlexion at hipDuration between 0.5 and 5 seconds
PERIODIC LIMB MOVEMENTSPeriodic limb movements during sleep (PLMS)Series of at least four individual leg movements in successionNo less than 5sec and no more than 90 sec apart
QUANTIFICATION OF PLMS Periodic limb movement index (PLMI): total number of
periodic limb movements per hour of sleep
PLMI: anywhere between 0 and 150 More typically PLMI between 30 and 60
PLM arousal index (PLMAI): total number of PLMS followed by EEG arousal per hour of sleep; PLMAI > 5
Polysomnography Report
Patient: DOB:
Gender: Male BMI: 42.2
Study Date:
Referring physician: JOHN Smith M.D.
Indications: Referred to rule out Sleep Apnea.
Symptoms: snoring, sleepiness
Epworth sleepiness scale: NA
Co-morbidities: HTN, DM
Diagnosis: Obstructive Sleep Apnea 327.23
*****************************************************************************
IMPRESSION:
1. Severe Obstructive Sleep Apnea Syndrome: The patient has an overall Apnea
Hypopnea Index (AHI) of 32.5/hr. on this study as well as severe oxygen
desaturation.
2. Hypoxemia: The patient was saturating 80-84% without oxygen. While on 2 lpm
oxygen, saturations were for the most part above 90%. Sleep apnea did continue
even on oxygen.
RECOMMENDATIONS:
In lab CPAP titration given hypoxemia
SUMMARY OF DATA:
SLEEP ARCHITECTURE:
Polysomnography was performed on the night of 7/11/2015 from 22:45:17 until
05:41:48. The Time-in-Bed, Sleep-Period Time, Total-Sleep Time, and Sleep
Efficiency (TST/TIB) were 423.6 minutes, 407.0 minutes, 324.5 minutes, and
77.9%, respectively. The sleep latency and stage N2 latency were 9.5 and 0.5
minutes, respectively. REM latency was 171.0 minutes. The sleep architecture
was as follows:
Minutes % TST
Wake Time after Sleep Onset: 82
Stage N1: 34 10
Stage N2: 191 59
Stage N3: 50 15
REM: 48 14
Sleep efficiency TST/TIB: 77.9%
AROUSALS:
There were a total of 79 arousals with an arousal index of 14.6/hr. Of those,
31 were respiratory related, 9 were PLM related and 39 were spontaneous.
RESPIRATORY:
The Apnea-Hypopnea Index through the night was 34.4/hr. The REM AHI was 37.5.
The supine AHI was 61.3.
Number Index (p/hr. sleep)
Obstructive Apneas: 10 1.8
Central Apneas: 0 0.0
Mixed Apneas: 0 0.0
Hypopneas: 174 30.7
Central Hypopneas: 0 0.0
Apnea-Hypopnea (AHI) 32.5
OXYGENATION:
With the patient awake and breathing ambient air, the average arterial oxygen
saturation was 90 % and during sleep the average arterial oxygen saturation
was 91 % with a nadir arterial oxygen saturation of 0 %. Time spent below 90%
oxygen saturation was 179.8 minutes and 55.4 % of total sleep time. The
oxygen desaturation index (4%) was 8.9. The oxygen desaturation index (3%)
was 16.3.
CARDIAC:
The mean heart rate was 84 bpm.
Cardiac arrhythmias:
Bradycardia: No
Sinus Tachycardia: No
Wide Complex Tachycardia: No
Narrow Complex Tachycardia: No
Asystole: No
Atrial Fibrillation: No
Other arrhythmias: Occasional PVCs noted
MOVEMENT EVENTS:
There were 239 periodic limb movements during sleep for a periodic limb
movement index (PLMI) of 44.2/hr. There were 9 periodic limb movements during
sleep associated with arousal for a periodic limb movement arousal index
(PLMAI) of 1.7.
WHAT’S NEXT
If you do have sleep apnea Continuous positive airway pressure therapy
WHAT’S NEXT
If you do have sleep apnea Oral appliance therapy
WHAT’S NEXT
If you don’t have sleep apnea
Depends on symptoms that you do have You are sleepy You could have another sleep disorder Should see an experienced sleep physician
You snore loudly Oral appliance Sleep on your side
Q & A
3006 Bee Caves Rd. | Suite D206 | Austin, TX 78746 | 512.366.9109 [email protected]
SLEEP STUDY: WHAT’S IT ALL ABOUTBRIAN KOO, M.D.